DE4234989A1 - COMPRESSOR WITH VARIABLE FLOW RATE - Google Patents

Description

The invention relates generally to compressors variable delivery rate. In particular, the Invention on an improved control mechanism the angle of inclination of a swash plate of the compressor in Agreement with a pressure difference between one Crank chamber as well as a suction chamber to the compression regulate the flow rate in a suitable manner.

With conventional compressors with variable delivery rates (Variable displacement compressors), for example, a cooling gas in a suction chamber sucked and com in a cylinder bore primed, whereupon it emerged through a discharge chamber formed discharge opening is promoted. The compression Flow rate is determined by the angle of inclination of a swash plate regulated. The cooling gas is also used inside regulate pressure in each of the associated chambers. If the cooling gas from the discharge chamber into the crank chamber is then an increase in the internal pressure in the Crank chamber caused. In contrast, the cooling gas from the Crank chamber fed into the suction chamber to the inside pressure in the crank chamber to relieve its pressure reduce. The internal pressures in the intake and crank chamber act on a piston, which is on the swash plate gert, causing the swash plate to tilt a corresponding change is brought. If the pressure is increased in the crank chamber, so the angle of inclination the swash plate correspondingly reduced and consequently also reduce the compression delivery rate of the compressor nert. If there is a drop in the internal pressure in the crank Chamber is caused, so the angle of inclination Swashplate enlarged and the compression output of the Compressor increased.  

The attached FIG. 7 shows a conventional compressor of this type. In this compressor, a bearing element 101 which is rotatable in one piece with it is held on a drive shaft 100 . In the bearing element 101 , an elongated hole 108 is formed, which serves as a guide to hold a connecting pin 109 slidably. A driver plate or disk 102 is rotated integrally with the bearing element 101 and inclined according to the sliding movement of the connecting pin 109 along the elongated hole 108 . With the carrier plate 102 is connected to a swash plate 103 which does not rotate due to a stop or locking element 104 together with the driver plate 102nd When the swash plate 103 is pivoted due to the rotational movement of the driving plate 102 , the swash plate 103 drives a plurality of pistons 105 which are arranged in a circumference and perform a reciprocating movement to compress the cooling gas.

The internal pressure Pc in the crank chamber 106 acts on the rear surface of the piston 105 , while the internal pressure Ps in the suction chamber 107 acts on the front surface of the piston 105 . The force applied to the piston 105 is transmitted to the swash plate 103 and from there then to the slave plate 102 . Under the force exerted on the driving plate 102 , the connecting pin 109 is brought to a displacement movement along the elongated hole 108 , as a result of which the angle of inclination of the driving plate 102 is changed. In this respect, the angle of inclination of the swash plate 103 is also changed with reference to the difference between the internal pressures in the two spaces 106 and 107 . Therefore, the inclination angle of the swash plate 103 , which determines the piston stroke, is adjusted by appropriately controlling the compressed delivery amount of the compressor.

As shown in the accompanying FIG. 8, a channel 112 connects the crank chamber 106 and the discharge chamber 110 . A throttle 111 is arranged in the channel 112 in order to prevent pressure leakage from the crank chamber 106 to the discharge chamber 110 . In this respect, the internal pressure in the crank chamber 106 cannot suddenly drop. Consequently, the inclination angle of the swash plate 103 , which determines the piston stroke, is suitably maintained by regulating the compressed delivery amount of the compressor.

In this construction, the compressor has the throttle 111 between the crank chamber 106 and the discharge chamber 110, and both spaces are connected to each other by the passage 112 . However, leakage of the cooling gas from the discharge chamber 110 into the crank chamber 106 cannot be completely eliminated. As a result, the cooling ability of the compressor or the gas as well as the cooling effect is reduced and the power loss is increased.

To avoid this disadvantage, JP Patent OS No. 62-191 673 proposes another conventional compressor, which is partially shown in the accompanying FIG. 9. This compressor has a switching valve 117 through which a suitable passage between a first passage 114 and a second passage 115 which connect the crank chamber 106 and the suction chamber 107 on the one hand, and also between a third passage 116 which is connected to the crank chamber 106 and the discharge chamber 110 is connected, is chosen to close the selected by the switching valve 117 through, wherein the switching operation of the valve 117 is effected on the basis of the pressure in the discharge chamber 110 and to suction chamber 107 corresponding force.

When the internal pressure Pd in the discharge chamber 110 is higher than the predetermined value (the value is set based on normal operation of the compressor at normal load), the switching valve 117 is switched so as to close the second and third passages 115 and 116 shut down. In this way, even if the compressor is operated under a maximum compression flow rate, pressure leakage from the discharge chamber 110 into the cure belkammer 106 is prevented by the third channel 116 . When the internal pressure in the suction chamber 107 is made to drop below the predetermined value, a switching valve arranged in the first passage 114 is operated to close this first passage 114 . If the internal pressure in the suction chamber 107 is higher than the predetermined value, the aforementioned switching valve is actuated to open the first passage 114 , so that the suitable internal pressure Pc is maintained in the cure chamber 106 .

If the internal pressure Pd in the discharge chamber 110 is lower than the predetermined value (the compressor is operated under a low load), the switching valve 117 is switched so that it closes the first passage 114 and opens the second and third passages 115 and 116 . In the second passage 115 , a throttle 118 is arranged, which causes the pressure in the crank chamber 106 through the suction chamber 107 and the second passage 115 to be lower than the pressure in the discharge chamber 110 through the crank chamber 106 and the third passage 116 . The inclination angle of the swash plate 103 is changed with the predetermined value to prevent a decrease in the compression output.

In the compressor described, the primary goal is to keep the internal pressure in the crank chamber 106 generally constant when the compressor is operating at the maximum delivery rate. Therefore, the third passage 116 is temporarily closed when the internal pressure in the discharge chamber 110 is increased beyond the predetermined value. As a result, the discharge chamber 110 and the crank chamber 106 are separated from each other even if the compressor is not operated at the maximum delivery rate. The increase in the internal pressure in the crank chamber 106 is based solely on the leak gas. This causes the response time for a decrease in the magnitude of the inclination angle of the swash plate 103 to be reduced or deteriorated.

It is therefore the primary object of this invention a compressor with variable delivery rate (adj compressor) to create exactly the compression regulates quantity.

An object of the invention is to make an adjustment compressor to create a rapid change in Nei tion angle of the swash plate, while doing a good responsiveness or responsiveness is maintained.

To solve the task and the stated goal as well as others Achieving goals is in accordance with the present Invention an improved variable compressor beat. This variable compressor includes a suction chamber which receives a cooling gas, and a plurality of back and forth outgoing piston, which is supplied from the suction chamber Compress the cooling gas within the assigned holes. Of this compressor also has a swiveling swash disc to in accordance with the pan or tilt angle regulate the piston stroke, a crank chamber around which Swashplate inclination angle according to the difference between the internal pressures in the intake and the crank chamber mer to regulate an ejection chamber to the compressed To discharge cooling gas, a first channel that came the intake mer with the crank chamber and the pressure of the cure Belkammer transmits to the suction chamber, and a second Ka  nal that connects the crank chamber with the discharge chamber as well as a restriction or throttle and the pressure of the Ejection chamber transfers to the crank chamber.

The features and advantages of the invention will be apparent from the fol given description of reference to the drawings preferred embodiments of the subject matter of the invention clear. Show it:

Fig. 1 shows an axial section of a compressor according to the invention;

Fig. 2 and 3 are enlarged sectional views of Einzelhei th a channel and passage construction of the compressor of Fig. 1, wherein Fig. 2 shows a channel opening valve and Fig. 3 shows the valve in its channel closing position;

Figures 4 to 6 partial sectional views similar to Figure 2, the modifications of the subject invention, respectively..;

Fig. 7 is an axial section of a conventional compressor;

Fig. 8 is a schematic illustration of pressures transmitted to the channels in the conventional compressor;

Fig. 9 is a schematic representation of pressures transmit the channels in another conventional compressor.

Referring to FIG. 1, a front housing member 2 is connected to the front end face of a cylinder block 1, while a back teres housing part 4 verbun with the rear end face of the Zylin derblocks 1 with the interposition of a valve plate 3 is the. In a certain in the front housing part 2 Kur belkammer 5 , a drive shaft 6 is arranged, which is rotatably supported by a pair of radial bearings 7 a and 7 b. In the cylinder block 1, a plurality of cylinder bores 8, only one of which is shown disposed around the radial bearing 7 b around. The cylinder bores 8 are connected to the crank chamber 5 . A piston 9 is slidably received in each cylinder bore 8 , and a compression chamber 10 is delimited between the piston 9 and the valve plate 3 .

On the rotating drive shaft 6 , a drive plate 11 is mounted within the crank chamber 5 so that it can be rotated as a part with the drive shaft 6 . Furthermore, a sleeve 12 is slidably held on the drive shaft 6 . Between the drive plate 11 and the sleeve 12 , a compression spring 13 is inserted which loads the sleeve 12 in Rich direction to the rear housing part 4 .

On the sleeve 12 by means of a right and left Ver connecting pin 14, a pivot bearing 15 is mounted such that it can swing or be pivoted. The pivot bearing 15 is of an annular shape, it surrounds the drive shaft 6 and carries a support arm 15 a, which projects in the direction of the driving plate 11 . The drive plate 11 is equipped with a bearing arm 11 a, which projects to the side of the rear housing part 4 and in which an elongated hole 16 is formed. At the free end of the support arm 15 a, a guide pin 17 is formed, which is slidably guided in the slot 16 . The engagement between the elongated hole 16 and the guide pin 17 gives the pivot bearing 15 the ability to pivot back and forth or rock and to rotate as a part with the drive shaft 6 and the drive plate 11 .

A swash plate 18 , which surrounds the drive shaft 6 , is attached to the circumference of the rotary bearing 15 via a thrust bearing 19 . The swash plate 18 is in operative connection with the associated pistons 9 , which are arranged on the circumference, via a plurality of connecting rods 20 , which are equally spaced on the circumference. On the swash plate 18 , a stop or locking element 21 of spherical shape is attached, which is slidably inserted into a sliding groove 22 , which is configured in the inner wall of the crank chamber 5 , to prevent the one-piece rotary movement of the swash plate 18 with the pivot bearing 15 . In this respect, the swash plate 18 can be pivoted back and forth without performing a rotational movement with respect to the rotational movement of the drive shaft 6 and the rotary bearing 15 . Each of the pistons 9 is moved back and forth linearly within its respective bore 8 by the forward and backward movement of the swash plate 18 .

The interior of the rear housing part 4 is divided into a suction chamber 24 and an exhaust chamber 25 by a partition 23 . The valve plate 4 is provided with a plurality of suction openings 26 and discharge openings 27 , which are formed in the respective cylinder bores 8 . Each compression chamber 10 communicates with the suction chamber 24 or the discharge chamber 25 through an associated suction opening 26 or discharge opening 27 . Each suction opening 26 and discharge opening 27 is blocked by a suction valve 28 or discharge valve 29 . If the piston 9 is in the intake process, the intake valve 28 is opened and the exhaust valve 29 is brought to close. In the exhaust stroke of the piston 9 , the suction valve 28 is brought to close and the exhaust valve 29 is opened. Each suction chamber 24 and discharge chamber 25 has a suction channel 30 and discharge channel 31 . Through the above-described element, the compressor is connected to a cooling circuit (not shown) of a cooling device.

On the outer wall of the rear housing part 4 , a valve receiving part 32 is formed by the extension thereof, which lies in the course of a channel 33 which connects the crank chamber 5 with the suction chamber 24 . A flow regulating automatic control valve 51 is accommodated in the receiving part 32 .

On the side facing the crank chamber 5 of the Ven valve-receiving part 32 , a connecting piece 34 is arranged, in which a narrow bore 36 is formed, through which the receiving part 32 can be brought into connection with the crank chamber 5 . On the base part 38 of the control valve 51 , a bellows 40 is fastened, by means of which the receiving part 32 is closed. In the bellows 40 , a gas with a predetermined pressure is kept in a sealed manner. On the basis of the gas pressure in the bellows 40 and that in the valve receiving part 32 corresponding pressure difference, the bellows 40 is expanded or contracted men. At the lower or free end of the bellows 40, there is a valve needle 41 which is inserted or pulled out of the narrow bore 36 due to the expansion or contraction movement of the bellows 40 . The pressure Pc in the crank chamber 5 is controlled in such a way that on the basis of the opening or closing movement of the valve needle 41 with respect to the narrow bore 36, the crank chamber 5 is connected to or separated from the suction chamber 24 .

Between the crank chamber 5 and an opening 35 in the Ven tilplatte 3 through the cylinder block 1 through a channel 42 is formed which connects the discharge chamber 25 and the crank chamber 5 . As shown in FIGS. 2 and 3, the channel 42 comprises a connecting bore 50 which connects the Ventilplat te 3 and a valve chamber 43 configured adjacent to this valve plate te. Furthermore, the bore 50 connects the crank chamber 5 and the valve chamber 43 . A control piston 44 used as a control valve V is arranged in the valve chamber 43 and is loaded or pressed against the valve plate 3 by the pressure force of a compression spring 45 towards the valve plate 3 . In the control piston 44 , a passage 47 is formed which connects the opening 35 and the connecting hole 50 Ver. On the side facing the valve plate 3 of the passage 47 a Dros selstelle 48 is included in this. On the front side (the side facing the front housing part 2 ) of the control piston 44 , a shut-off element 46 of spherical shape is present, which can be inserted into a recess 47 'or removed from it, this recess 47 ' being a conical or rounded, for Connecting hole 50 directed towards and forms an open seat.

The pressure Pd in the discharge chamber 25 acts through the opening 35 on the rear face of the control piston 44 , while the pressure Pc in the crank chamber 5 acts through the channel 42 on the front face of this control piston 44 . When the compressor is operated at the maximum discharge amount, the maximum discharge pressure Pdmax generated in the discharge chamber 25 is set by adjusting the pressing force Pp of the compression spring 45 so that the following equation Pdmax <Pc + Pp is satisfied . Therefore, the spool 44 is made to close when the compressor is operated at the maximum flow rate.

As shown in Fig. 2, the spool 44 is in the open position when the compressor is operating near the maximum flow rate at high load, but does not reach the maximum flow rate. In this respect, the following equation Pd <Pc + Pp is always fulfilled. If the control piston 44 is opened, the cooling gas in the discharge chamber 25 is discharged from the opening 35 into the crank chamber 5 through the valve chamber 43 , the passage 47 of the control piston 44 and the connecting bore 50 .

As a result, an increase in the internal pressure in the crank chamber 5 is caused. The rapid flow of the cooling gas from the discharge chamber 25 to the crank chamber 5 and the rapid increase in internal pressure in the crank chamber 5 and the rapid decrease in internal pressure in the discharge chamber 25 are prevented by the throttle 48 in the passage 47 . The compression flow rate is changed continuously or uniformly in order to achieve stable operation of the compressor.

If the compressor is operated at the maximum delivery rate, the swash plate 18 is brought to a back and forth swing depending on the rotational movement of the drive shaft 6 . The cooling gas is compressed by the reciprocating movement of the pistons 9 in the cylinder bores 8 . The pressure Pc in the crank chamber 5 is controlled by the automatic control valve 51 . The inclination angle of the swash plate 18 is changed in accordance with the difference between the pressure Pc in the crank chamber 5 and the pressure Ps in the suction chamber 24 to control the compression discharge amount. The control piston 44 is brought to open within the valve chamber 43 incorporated into the channel 42 . The cooling gas is caused to flow into the crank chamber 5 by the discharge chamber 27 , so that the inclination angle of the swash plate 18 is reduced.

If the compressor is operated at the maximum delivery rate, as shown in FIG. 3, the control piston 44 is brought within half of the valve chamber 43 to close the channel 42 . Therefore, the cooling gas does not flow from the discharge chamber 25 to the crank chamber 5 . As a result, the compressor is operated reliably and without loss in its cooling capacity and performance.

Although only one specific embodiment above form of this invention has been described, it should be understood that the expert with knowledge of the teaching imparted an objection lungs and changes of numerous kinds to the described Embodiment are suggested, but as in the Rah  men of the invention are to be considered falling. In particular, should te be clear that the construction of the Control piston can be modified.

FIGS. 4 and 5 show executive form a further off according to the invention, wherein the shut-off element is 46 44 replaces the control piston by means of a differently designed control piston 44, the end face on which the Verbindungsboh tion 50 side facing frustoconical or as a straight (in Fig. 5 perpendicular ) Wall surface is formed. The recess 47 'is formed with a shape corresponding to the closing surface of the control piston 44 . With this construction, the shut-off element 46 can be omitted, so that the manufacturing process is simplified and the manufacturing costs are reduced.

In a further embodiment shown in FIG. 6, the control valve V only consists of a control element 44 a of a spherical shape. If the pressure Pd in the ejection chamber 25 exceeds the predetermined value, the control element 44 a is brought to a movement in the closing direction against the compressive force of the coil spring 45 . If the control element 44 a is in the open position, the cooling gas in the discharge chamber 25 , the flow of which is regulated by the throttle 48 in the connecting bore 50 , is introduced into the crank chamber 5 .

The regulation of the compression flow rate is less effective in this embodiment than in the other embodiments. Since the throttle 48 is formed in the connecting bore 50 , for example, the pressure Pd in the discharge chamber 25 and the pressure on the control element 44 a side act through the throttle 48 of the connecting bore 50 on the control piston 44 a of the control valve V. Therefore, the Pressure Pc in the crank chamber 5 , which regulates the angle of inclination of the swash plate 18 , does not reflect precisely.

On the other hand, the throttle 48 , which is essential to prevent the rapid pressure drop in the discharge chamber 25 and the crank chamber 5 , is received within the channel 42 . Therefore, the pressures Pc and Pd in the crank chamber 5 and the discharge chamber 25 , which act on both end faces of the control piston 44 , do not act through the throttle 48 . As a result, the process for opening or closing the channel 42 is controlled based on the pressure Pc which is directly related to the inclination angle of the swash plate 18 . As a result, the amount of compression is regulated or adjusted with high precision.

The invention thus discloses an improved Verkomkom Swashplate type pressor, in which cooling gas by col ben compressed and the gas from a discharge chamber is promoted. The piston stroke is in accordance with regulated the swivel angle of the swash plate, which by the size of the internal pressure of the crank chamber ver will change. A first channel connects an intake chamber with the crank chamber to adjust the pressure of the crank chamber Transfer suction chamber. A second channel connects the Crank chamber with the discharge chamber to the pressure of the discharge chamber to the crank chamber via a throttle if the difference between the pressures inside the ejection chamber and the crank chamber above one agreed value.

It is clear that the examples and implementation described only form the explanation and the invention do not limit object.

Claims (7)

1. compressor with variable flow rate, the a cooling gas receiving suction chamber ( 24 ), a plurality of reciprocating pistons ( 9 ) that compress the cooling gas supplied from the suction chamber ( 24 ) within the associated bores ( 8 ), a ver pivotable Swashplate ( 18 ), which controls the piston stroke in accordance with the swivel angle, a Kur belkammer ( 5 ), which be the swivel angle of the swashplate ( 18 ) in accordance with the difference between the internal pressures in the suction chamber ( 24 ) and the crank chamber ( 5 ) adjusts a discharge chamber ( 25 ) which discharges the compressed cooling gas, a first channel ( 33 ) which connects the suction chamber ( 24 ) with the crank chamber ( 5 ) and transfers the pressure of the crank chamber to the suction chamber, and a second channel ( 42 ), which connects the crank chamber ( 5 ) with the discharge chamber ( 25 ) and transfers the pressure of the discharge chamber to the crank chamber , characterized thereby calibrates that a constriction ( 48 ) is contained in the second channel ( 42 ). 2. Compressor according to claim 1, characterized in that the second channel ( 42 ) contains a control valve (V) which opens the second channel when the pressure of the discharge chamber ( 25 ) is higher than that of the crank chamber ( 5 ) by a predetermined value. is. 3. Compressor according to claim 2, characterized in that the control valve (V) with an inner passage ( 47 ) is seen ver, which transmits the pressure from the discharge chamber ( 25 ) to the side of the crank chamber ( 5 ). 4. Compressor according to claim 2 or 3, characterized in that the constriction ( 48 ) in the course of the inner passage ( 47 ) of the control valve (V) is formed. 5. A compressor according to claim 1, characterized in that the first channel ( 33 ) contains a pressure control valve ( 51 ) which transfers the pressure in the crank chamber ( 5 ) as a function of the pressure within the suction chamber ( 24 ) to the suction chamber. 6. Compressor according to claim 1, characterized by a rotating drive shaft ( 6 ), a drive shaft firmly connected to the drive shaft ( 11 ), on the drive shaft to a displaceably mounted sliding sleeve ( 12 ) as a rotary bearing ( 15 ) with the sleeve ( 12 ) is pivotally connected to the bar and is coupled to the drive plate ( 11 ) for a uniform rotation and pivoting movement, the pivot bearing ( 15 ) supporting the swash plate ( 18 ) for rotation with respect to the sem. 7. A compressor according to claim 6, characterized in that the swash plate ( 18 ) with a in the inner wall of the crank chamber ( 5 ) formed throat ( 22 ) in engagement locking element ( 21 ) which rotates the swash plate together with that of the Drehla gers ( 15 ) prevented.